Apparatus for manufacturing solid fuel using combustible waste

ABSTRACT

There is provided an apparatus for manufacturing solid fuel using combustible waste, to manufacture RPF or RDF by melting general waste and combustible waste as well as the waste plastics, such as waste tires, waste vinyl and PET bottles, by using heat generated in a combustion apparatus. The apparatus for manufacturing the solid fuel comprises: combustion equipment constituted by including a combustion apparatus, an ignition burner, a fuel throwing opening for throwing combustible waste into a combustion chamber, a ventilation unit for supplying air to the combustion chamber, and an outlet for discharging heat and gas generated upon combustion; and a heating chamber connected to the outlet and including a plurality of combustible waste supply pipes inside, and wherein an extruder with a spiral screw formed around a rotation shaft rotating by a motor is built in each combustible waste supply pipe, a hopper for supplying shredded combustible waste is positioned at an end of the extruder towards the motor, and an extrusion nozzle for extruding melted combustible waste is formed at the other end of the extruder.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No. 2007-126249, filed on Dec. 12, 2006, the disclosure of which is hereby incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to an apparatus for manufacturing solid fuel using combustible waste and, more particularly, to an apparatus for manufacturing solid fuel using combustible waste, which manufactures RPF or RDF by melting general waste and combustible waste as well as the waste plastics, such as waste tires, waste vinyl and PET bottles, by use of heat generated in a combustion apparatus.

2. Discussion of Related Art

Synthetic resin products, such as tires, vinyl, plastics and the like are widely used in various industrial fields and daily life. Only parts of the synthetic resin products are recycled after use, and most synthetic resin products are classified as waste to be buried or burned out. Since plastic waste is bulky compared to weight, the cost of burying the plastic waste is higher than the cost of burying general waste. Moreover, even though the plastic waste is buried, since it is not biodegradable, it is regarded as a social problem.

In particular, a recycling rate of waste plastics is lower than that of the other waste. Specifically, during the period of one year of 2005, the recycling rates are respectively 55% for waste paper, 67% for waste tires, 58% for glass bottles and 43% for scrap iron while the recycling rate of plastics is about 15%. Moreover, waste plastics are generated by 4 to 5 million tons every year, and a generation rate thereof also remarkably increases every year. In these circumstances, to enhance the recognition that waste plastics are one of resources and to increase the recycling rate of waste plastics, the Ministry of Environment has notified the public of the quality and standard basis of solid fuel products using waste plastics and has positively supported people to use the solid fuel products as substitute fuel. As a result, in view of a long term, the recycling rate of waste plastics is expected to increase up to 50%, to have the economical effect of 500,000,000,000 Korea Won per year.

Meantime, considering the aforementioned reality, many techniques for manufacturing RDF (refuse derived fuel: solid fuel products using living waste) and RPF (refuse plastic fuel: solid fuel products using plastic waste) have been filed and registered. The RDF is manufactured by processing combustible waste among the living waste, and the RPF is manufactured by processing plastic waste.

For example, as a conventional technique, Korean Utility Model Registration No. 407,477 relates to the combustion apparatus for renewable energy, in which a fuel outlet is formed at a combustion burner. In this literature, the combustion apparatus of burning the renewable energy is described in detail. However, in the specification or drawings of this literature, there is not specified or illustrated a waste plastic extruder for producing reclaimed solid fuel using waste by thermal energy generated in the combustion apparatus, or the specific technical contents of manufacturing the reclaimed solid fuel.

As another conventional technique, Korean Patent Registration No. 321,378 relates to an apparatus for manufacturing solid fuel formed of combustible waste by using thermoplastics, which is illustrated in FIG. 1. In the technical constitution, combustible waste stored in a hopper 10 is supplied to a molding tube 20 with a number of heating bands 21 through a rotation supplier 11. When a pusher 32 is pushed by converting a rotation force of a motor 30 into a linear reciprocating motion, solid fuel is pressed between a fixing plate 41 formed at one side end of the molding tube 20 and the pusher 32. After the solid fuel is press-molded, the pusher 32 moves back and simultaneously an outlet 40 is opened to discharge the molded solid fuel.

However, since the aforementioned apparatus for manufacturing the solid fuel has the constitution of pushing out the solid fuel being press-molded, it cannot continuously produce the solid fuel so that the productivity is low. Moreover, since the waste inside the molding tube is melted by mounting the heating bands onto the outer circumference of the molding tube, a lot of energy, such as electric energy, for heating the heating bands is needed. Moreover, since the rotation supplier for supplying the combustible waste needs to be intermittently operated, another device for controlling the rotation supplier is needed, so that the entire constitution of the apparatus is very complicate.

SUMMARY OF THE INVENTION

Therefore, the present invention is directed to provide an apparatus for manufacturing solid fuel using combustible waste, which significantly reduces energy expenses for manufacturing the solid fuel, such as RPF or RDF, by manufacturing the solid fuel by melting combustible waste by use of heat of combustion in a combustion apparatus using renewable energy (RPF, RDF or combustible waste) as fuel.

Another object of the present invention is to provide an apparatus for manufacturing solid fuel using combustible waste, which improves the productivity of solid fuel and produces various kinds of the solid fuel with a maximized pressing force simultaneously, by improving the structure of a solid fuel extruder for manufacturing the solid fuel, such as RPF or RDF.

In accordance with an embodiment of the present invention, there is provided an apparatus for manufacturing solid fuel using combustible waste, comprising: combustion equipment constituted by including a combustion apparatus, an ignition burner, a fuel throwing opening for throwing combustible waste into a combustion chamber, a ventilation unit for supplying air to the combustion chamber, and an outlet for discharging heat and gas generated upon combustion; and a heating chamber connected to the outlet and including a plurality of combustible waste supply pipes inside, and wherein an extruder with a spiral screw formed around a rotation shaft rotating by a motor is built in each combustible waste supply pipe, a hopper for supplying shredded combustible waste is positioned at an end of the extruder towards the motor, and an extrusion nozzle for extruding melted combustible waste is formed at the other end of the extruder.

Preferably, the outlet of the combustion equipment may be connected to a divided chamber, a number of divided pipes may be divided form the divided chamber, and each divided pipe may be connected to the heating chamber where the combustible waste supply pipe is installed.

Preferably, the rotation shaft of the extruder may have a diameter which progressively becomes bigger towards the end or the spiral screw formed about the rotation shaft may have a pitch interval which becomes narrower towards the end.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present invention will become more apparent to those of ordinary skill in the art by describing in detail preferred embodiments thereof with reference to the attached drawings in which:

FIG. 1 is a sectional view illustrating a conventional apparatus for manufacturing solid fuel using combustible waste;

FIG. 2 is a sectional view illustrating an apparatus for manufacturing solid fuel according to a first embodiment of the present invention;

FIG. 3 is a plan view illustrating a heating chamber according to the first embodiment;

FIG. 4A is a sectional view illustrating a waste supply pipe and an extruder according to the present invention;

FIG. 4B is a plan view of an extrusion nozzle;

FIGS. 5A and 5B are respectively a sectional view and a partially enlarged plan view illustrating a waste supply pipe and an extruder according to a second embodiment of the present invention;

FIG. 6 is a sectional view illustrating combustion equipment according to the second embodiment;

FIG. 7 is a sectional view illustrating combustion equipment according to a third embodiment;

FIG. 8 is a sectional view illustrating an apparatus for manufacturing solid fuel according to the second embodiment; and

FIG. 9 is a sectional view illustrating a heating chamber according to the second embodiment.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein.

An apparatus for manufacturing solid fuel using combustible waste according to the present invention will be described with reference to FIGS. 2 through 9.

FIG. 2 is a sectional view illustrating an apparatus for manufacturing solid fuel according to a first embodiment of the present invention, FIG. 3 is a plan view illustrating a heating chamber according to the first embodiment, FIG. 4A is a sectional view illustrating a waste supply pipe and an extruder according to the present invention, FIG. 4B is a plan view of an extrusion nozzle, FIGS. 5A and 5B are respectively a sectional view and a partially enlarged plan view illustrating a waste supply pipe and an extruder according to a second embodiment of the present invention, FIGS. 6 and 7 are sectional views illustrating combustion equipment according to different embodiments, FIG. 8 is a sectional view illustrating an apparatus for manufacturing solid fuel according to the second embodiment, and FIG. 9 is a sectional view illustrating a heating chamber according to the second embodiment.

As illustrated in FIG. 2, an apparatus for manufacturing solid fuel according to a first embodiment of the present invention comprises: combustion equipment 100 constituted by including a combustion apparatus 110, an ignition burner 120, a fuel throwing opening 130 for throwing combustible waste into a combustion chamber 105, a ventilation unit 140 for supplying air to the combustion chamber 105, and an outlet 150 for discharging heat and gas generated upon combustion; and a heating chamber 200 connected to the outlet 150 and including a plurality of combustible waste supply pipes 210 inside, wherein an extruder 211 with a spiral screw 214 formed around a rotation shaft 213 rotating by a motor 215 is built in each combustible waste supply pipe 210, a hopper 220 for supplying shredded combustible waste is positioned at an end of the extruder 211 towards the motor 215, and an extrusion nozzle 230 for extruding melted combustible waste is formed at the other end of the extruder 211.

In the combustion equipment 100, the combustion apparatus 110 for burning the combustible waste will bed described. Rotating by a rotation force of a motor 111, the combustion apparatus 110 according to the first embodiment as illustrated in FIG. 2 burns fuel (RDF, RPF or combustible waste) which is thrown or dropped in an upper part thereof. The combustion apparatus 110 has a structure in which a bottom of the combustion apparatus 110 becomes higher towards a rotation center in a staircase shape or conical shape. However the combustion apparatus may have another structure in which the bottom thereof becomes lower towards the rotation center in the staircase shape or conical shape (not shown). A number of nozzles 113 are positioned at each stair. Flames are formed through the nozzles, to burn the combustible waste. However, the combustion apparatus 110 rotates but it may have a level bottom as illustrated in a third embodiment (of FIG. 7).

The fuel used for burning in the combustion equipment 100 may be not only RDF and RPF but also anything that is the combustible waste. The fuel to be supplied to the combustion chamber 105 is stored in a hopper 131, rotated by a motor 133 and supplied to the combustion chamber 105 through an extruder 135 for transferring the fuel. Instead of the extruder 135, a cylinder (not shown) which intermittently operates may be used.

The fuel throwing opening 130 to supply the fuel to the combustion chamber 105 may be positioned at a sidewall of the combustion chamber 105 as illustrated in FIG. 2, it may be positioned at a bottom part of the combustion chamber 105 according to a second embodiment as illustrated in FIG. 6, or it may be positioned at a top part (ceiling) of the combustion chamber 105 according to the third embodiment illustrated in FIG. 7. The ventilation unit 140, such as an air blower to supply air (oxygen) for burning to the combustion chamber 105, is separately installed. For complete combustion inside the combustion chamber 105, the burning flames needs to be stay for a maximally long time, at high temperature, in the combustion chamber 105. Therefore, it is preferable to supply additional cold air by the ventilation unit 140 in the middle or at an upper part of the combustion chamber 105.

The heat and gas generated when the fuel is burned in the combustion equipment 100 are discharged to the heating chamber 200 through the outlet 150 positioned around an upper end of the combustion chamber 105. Since the heat of combustion flowing out through the outlet 150 after the combustion generally has high temperature of about 1,200 to 1,300° C., the ventilation unit, such as the air blower, is positioned between the outlet 150 and the heating chamber 200, to provide cold air so that the temperature inside the heating chamber 200 drops to 400° C. or below. When a distribution chamber 160 is connected to the outlet 150, preferably, the ventilation unit may be positioned between the outlet 150 and the distribution chamber 160.

As illustrated in FIG. 3, only one heating chamber 200 may be connected to the outlet 150 and a number of the waste supply pipes 210 may be installed inside the heating chamber 200, or as illustrated in FIG. 8, the distribution chamber 160 may be connected to the outlet 150 and each heating chamber 200′ may be connected to each of a number of divided pipes 161 which are divided from the distribution chamber 160. When each heating chamber 200′ is connected to each divided pipe 161, a divided pipe opening/closing unit (not shown) may be installed between the divided pipe 161 and the heating chamber 200′, to cut off the heat of combustion from the outlet 150 to each heating chamber 200′ so that only some of the heating chambers 200′ can be operated.

Further, when each heating chamber 200′ is connected to each divided pipe 161, a number of the waste supply pipes 210 may be installed in each heating chamber 200′ but preferably one waste supply pipe 210 may be installed in each heating chamber 200′. Considering the facility capacity or the control and management capability and the field situation and others, preferably the number of the waste supply pipes 210 or divided pipes 161 may be twenty (20) or under. Reference numeral 170 denotes an exhaust chamber for collecting the discharged heat and gas and sending the collected heat and gas to the post-facility for removing pollutants before the collected heat and gas are exhausted to the air.

The RDF or RPF melts the combustible waste to different extent, depending on a manufacturing temperature. Since the quality of the RDF or RPF varies according to the melted extent, preferably, the RDF or RPF may be manufactured at the temperature of about 150 to 400° C. To control the manufacturing temperature, it is desirable to control the temperature of the heating chamber 200 or 200′. Thus, preferably, a separate cooling chamber 300 may be installed at the front end of the heating chamber 200 or 200′, that is, around the combustible waste supply pipe 210 at the portion where the extrusion nozzle 230 is positioned, to provide the cold air through a separate ventilation unit (not shown) so that the waste supply pipe 210 is cooled down. Preferably, a temperature checking unit (not shown) for checking the temperature inside the heating chamber 200 or 200′, such as a temperature sensor or a thermometer, may be installed in the heating chamber 200 or 200′. More preferably, the operation of the ventilation unit may be controlled to be intermittent, according to the temperature inside the heating chamber 200 or 200′.

The waste supply pipe 210 is installed inside the heating chamber 200 or 200′. The extruder 211 is installed in each waste supply pipe 210. The extruder 211 is rotated by the rotation force of the motor 215. In the extruder 211, the spiral screw 214 is formed around the rotation shaft 213. When the waste shredded in small size (about the length of 1 to 3 ca) is supplied into the extruder 211 inside the waste supply pipe 210 through the hopper 220 positioned nearby the motor 215, the waste is melted by the heat of the heating chamber 200 or 200′ surrounding the waste supply pipe 210 at a predetermined space and the waste is pressed and transferred. The transferred waste is extruded through an extrusion opening 231 of the extrusion nozzle 230 installed at the end of the waste supply pipe 210. The melted and extruded waste is cut in a predetermined size by a cutting unit 217 installed at a front end of the extrusion nozzle 230 of the waste supply pipe 210, to be manufactured as solid fuel. Reference number 219 denotes a support for holding the solid fuel when the cutting unit 271 cuts the solid fuel.

Preferably, the number of the extrusion opening 231 formed in the extrusion nozzle 230 may be about 1 to 20, considering the size of the apparatus for manufacturing the solid fuel. The sectional shape of the extrusion opening 231 is round as illustrated in FIG. 4B but it may be various.

In the extruder 211, when a pitch interval of the spiral screw 214 formed on the outer circumferential surface of the rotation shaft 213 is formed so as to be narrower towards the end in a rotation direction, or when a diameter of the rotation shaft 213 is formed to be greater towards the end in the rotation direction, the melted and transferred waste can be more efficiently pressed to be transferred and extruded, so that the quality of the manufactured solid fuel is improved.

FIG. 4A illustrates one extruder 211 installed in one waste supply pipe 210 but FIG. 5A illustrates two extruders 211 installed in one waste supply pipe 210.

In FIGS. 5A and 5B, two extruders 211 are installed in one waste supply pipe 210. The extruders 211 built in the waste supply pipe 210 includes their respective spiral screws 214 which are twisted about their respective rotation shaft 213 in the opposite direction to each other. Then, the spiral screws 214 respectively twisted about the two rotation shaft in the opposite direction to each other are arranged to be alternated each other as illustrated. FIG. 5B illustrates the enlargement of Part “A” of FIG. 5A. Referring to FIG. 58, the two spiral screws 214 formed about their respective rotation shafts 213 need to have the same pitches (a) and (b), respectively. Then, the spiral screws 214 are to be installed, spaced apart from each other at a half-pitch distance (c) which is the middle of the pitch to each other.

As described above, in the apparatus for manufacturing fuel solid using combustible waste according to the present invention, since the fuel solid is manufactured by melting the combustible waste by using only the heat of combustion of the combustion apparatus using the renewable energy (RPF, RDF or combustible waste) as the fuel, without using any additional heating unit, the energy expenses for manufacturing the solid fuel, such as RPF or RDF, can be sharply reduced.

Furthermore, in the apparatus for manufacturing the fuel solid, the extruder on which the spiral screw is formed is used as the unit for transferring the combustible waste. Therefore, since the combustible waste is transferred not intermittently but continuously, the productivity of manufacturing the solid fuel, such as RPF or RDF, is improved. Further, since the structures of the extruder and the extrusion nozzle are improved, various kinds of quality solid fuel with a maximized pressing force can be produced simultaneously.

Furthermore, as the solid fuel, such as RPF or RDF, which is manufactured by the apparatus for manufacturing solid fuel according to the present invention substitutes for heavy oil or light oil which has been used as the heating oil in the central heating of a large-scale public housing complex or in the places where large-scale heating is needed, such as a cement factory, a dye house, an electric power generation plant, an iron mill, an industrial boiler factory, an inland water farm, a flowering and gardening farm and the like, tremendous energy can be saved.

The invention has been described using preferred exemplary embodiments. However, it is to be understood that the scope of the invention is not limited to the disclosed embodiments. On the contrary, the scope of the invention is intended to include various modifications and alternative arrangements within the capabilities of persons skilled in the art using presently known or future technologies and equivalents. The scope of the claims, therefore, should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements. 

1. An apparatus for manufacturing solid fuel using combustible waste, comprising: combustion equipment constituted by including a combustion apparatus, an ignition burner, a fuel throwing opening for throwing combustible waste into a combustion chamber, a ventilation unit for supplying air to the combustion chamber, and an outlet for discharging heat and gas generated upon combustion; and a heating chamber connected to the outlet and including a plurality of combustible waste supply pipes inside, and wherein an extruder with a spiral screw formed around a rotation shaft rotating by a motor is built in each combustible waste supply pipe, a hopper for supplying shredded combustible waste is positioned at an end of the extruder towards the motor, and an extrusion nozzle for extruding melted combustible waste is formed at the other end of the extruder.
 2. An apparatus for manufacturing solid fuel using combustible waste, comprising: combustion equipment constituted by including a combustion apparatus, an ignition burner, a fuel throwing opening for throwing combustible waste into a combustion chamber, a ventilation unit for supplying air to the combustion chamber, and an outlet for discharging heat and gas generated upon combustion; a distribution chamber connected to the outlet; a number of divided pipes divided from the distribution chamber; and a heating chamber connected to each divided pipe and including a combustible waste supply pipe inside, and wherein an extruder with a spiral screw formed around a rotation shaft rotating by a motor is built in each combustible waste supply pipe, a hopper for supplying shredded combustible waste is positioned at an end of the extruder towards the motor, and an extrusion nozzle for extruding melted combustible waste is formed at the other end of the extruder.
 3. The apparatus according to claim 1, wherein the fuel throwing opening is installed on a sidewall of the combustion chamber.
 4. The apparatus according to claim 2, wherein the fuel throwing opening is installed on a sidewall of the combustion chamber.
 5. The apparatus according to claim 1, wherein the fuel throwing opening is installed on a top (ceiling) of the combustion chamber.
 6. The apparatus according to claim 2, wherein the fuel throwing opening is installed on a top (ceiling) of the combustion chamber.
 7. The apparatus according to claim 1, further comprising: a ventilation unit for supplying cold air, installed between the outlet and the heating chamber, to control a temperature inside the heating chamber.
 8. The apparatus according to claim 2, further comprising: a ventilation unit for supplying cold air, installed between the outlet and the distribution chamber, to control a temperature inside the heating chamber.
 9. The apparatus according to claim 7, further comprising: a cooling chamber for receiving the cold air supplied from the ventilation unit, installed around the combustible waste supply pipe at a front end of the heating chamber, i.e., at a part where the extrusion nozzle is formed.
 10. The apparatus according to claim 8, further comprising: a cooling chamber for receiving the cold air supplied from the ventilation unit, installed around the combustible waste supply pipe at a front end of the heating chamber, i.e., at a part where the extrusion nozzle is formed.
 11. The apparatus according to claim 1, wherein the extrusion nozzle includes one to twenty extrusion openings formed therein.
 12. The apparatus according to claim 2, wherein the extrusion nozzle includes one to twenty extrusion openings formed therein.
 13. The apparatus according to claim 1, wherein the spiral screw formed on an outer circumferential surface of the rotation shaft has a pitch interval becoming narrower towards an end in a rotation direction.
 14. The apparatus according to claim 2, wherein the spiral screw formed on an outer circumferential surface of the rotation shaft has a pitch interval becoming narrower towards an end in a rotation direction.
 15. The apparatus according to claim 1, wherein the rotation shaft has a diameter becoming greater towards the end in the rotation direction.
 16. The apparatus according to claim 2, wherein the rotation shaft has a diameter becoming greater towards the end in the rotation direction.
 17. The apparatus according to claim 1, wherein the extruder built in the combustible waste supply pipe is formed integrally with two spiral screws being respectively twisted about two rotation shafts in the opposite direction to each other.
 18. The apparatus according to claim 2, wherein the extruder built in the combustible waste supply pipe is formed integrally with two spiral screws being respectively twisted about two rotation shafts in the opposite direction to each other.
 19. The apparatus according to claim 1, further comprising: a cutting unit for cutting the melted and extruded combustible waste, installed at a front end of the extrusion nozzle.
 20. The apparatus according to claim 2, further comprising: a cutting unit for cutting the melted and extruded combustible waste, installed at a front end of the extrusion nozzle.
 21. The apparatus according to claim 2, further comprising: a divided pipe opening/closing unit for cutting off the heat flowing into the heating chamber, installed in each divided pipe.
 22. The apparatus according to claim 1, further comprising: an unit for checking a temperature, installed in the heating chamber.
 23. The apparatus according to claim 2, further comprising: an unit for checking a temperature, installed in the heating chamber.
 24. The apparatus according to claim 1, wherein the temperature inside the heating chamber is 150 to 400° C.
 25. The apparatus according to claim 2, wherein the temperature inside the heating chamber is 150 to 400° C.
 26. The apparatus according to claim 2, further comprising: an exhaust chamber for collecting the gas exhausted from each heating chamber. 